The subject matter disclosed herein relates to gas turbine combustors, and particularly to an annular ring-manifold quaternary fuel distributor, which is used to mitigate combustor instability, to provide better fuel/air mixing and improve flame holding margin of downstream fuel nozzles by accommodating up to 30%, by mass, of total combustor fuel.
Existing quaternary fuel pegs of a combustor are installed through the flow sleeve casing inner wall of, for example, combustors of gas turbine engines and are located in the annulus between the flow sleeve and cap barrel, which are upstream of combustor fuel nozzles. Their main function is to inject fuel into the flow of air or a fuel/air mixture and to mitigate combustion dynamics in and through the combustor during combustion operations.
The existing quaternary peg design is susceptible, however, to instances of flame-holding, which refers to the phenomena of unexpected flame occurrence immediately downstream of the quaternary pegs within combustors. Flame-holding can lead to damage to combustor hardware. The existing design also tends to generate relatively unsatisfactory quaternary fuel air mixing, which limits the capability to accommodate high quaternary fuel mass fraction, leading to unsatisfactory or limited quaternary fuel-air pre-mixing upstream combustor fuel nozzles.